DESCRIPTION (Adapted from application): The long term goal of this project is to develop antisense oligonucleotide, antisense vectors, and the delivery agents with favorable pharmacokinetics in vivo. The results of this work will provide the basis for future studies on the applicability of antisense oligonucleotides as therapeutic agents. Specifically, the investigator has developed an approach which exploits the ability of an antisense oligonucleotide to generate a new gene product by restoring proper mRNA splicing. Relative to targeting decreased gene expression, targeting increased gene expression is advantageous because it is less likely that increased gene expression might be due to non-sequence- selective or non target-direct interactions. Further development of this approach to provide cell specific, positive read-out assays for in vivo and in vitro assessment of antisense oligonucleotide efficiency is one of the main goals of this proposal. The five specific aims are: 1) Construct cell lines expressing enhanced green fluorescent protein (EBFP). EGFP will be interrupted by an aberrantly spliced human beta-globin intron and will be the oligomer target; EDFP will be an internal control. 2) Generate transgenic mice uniformly expressing EGFP and EBFP. 3) Perform comparative testing of chemically different oligomers in cell culture and animal models. 4) Perform comparative testing of a series of delivery agents (lipids, dendrimers, etc.) 5) Use the systems constructed in specific aims 1, 2 and 4 to test delivery of vector-expressed antisense RNA.